Here is what the Christian Gospels have to say about prayer:
“And when you pray, you shall not be like the hypocrites. For they love to pray standing in the synagogues and on the corners of the streets, that they may be seen by men. Assuredly, I say to you, they have their reward. But you, when you pray, go into your room, and when you have shut your door, pray to your Father who is in the secret place; and your Father who sees in secret will reward you openly.” [Matthew 6:5-6]
Jewish law and tradition holds that while all prayer is good, praying as a part of a minyan, a group of 10 or more, is an act of special holiness. Not everyone who prays in the presence of others is a hypocrite, and not everyone who prays alone is holy.